Authors: KeJing Huang DeJun Niu JunYong Sun XiaoLi Zhu JunJie Zhu
Publish Date: 2010/06/25
Volume: 397, Issue: 8, Pages: 3553-3561
Abstract
A novel experimental methodology based on a Prussian blue PB and gold nanoparticles AuNPs modified carbon ionic liquid electrode CILE was developed for use in a labelfree amperometric immunosensor for the sensitive detection of human immunoglobulin G HIgG as a model protein The CILE was fabricated by using the ionic liquid 1octyl3methylimidazolium hexafluorophosphate as binder Controllable electrodeposition of PB on the surface of the CILE and coating with 3aminopropyl triethylene silane APS formed a film with high electronic catalytic activity and large surface area for the assembly of AuNPs and further immobilization of HIgG antibody The electrochemistry of the formed nanocomposite biofilm was investigated by electrochemical techniques including cyclic voltammetry differential pulse voltammetry and electrochemical impedance spectroscopy The HIgG concentration was measured through the decrease of amperometric responses in the corresponding specific binding of antigen and antibody The decreased differential pulse voltammetric values were proportional to the HIgG concentration in two ranges 005–125 ng mL−1 and 125–40 ng mL−1 with a detection limit of 0001 ng mL−1 S/N = 3 This electrochemical immunoassay combined the specificity of the immunological reaction with the sensitivity of the AuNPs ionic liquid and PB amplified electrochemical detection and would therefore be valuable for clinical immunoassaysCyclic voltammograms of the immunosensor in pH 70 phosphatebuffered solution containing 01 M KCl at the different scan rate of from inner to outer 50 100 150 200 250 300 350 400 450 500 550 600 650 700 750 and 800 mVs−1 The inset shows the linear relationship between the peak currents and the square root of scan rateThis work was supported by National Natural Science Foundation of China 20805040 20635020 Excellent Youth Foundation of He’nan Scientific Committee 104100510020 China Postdoctoral Science Foundation funded project 200902508 20080430163 Jiangsu Planned Projects for Postdoctoral Research Funds 0801041B and sponsored by Program for Science Technology Innovation Talents in Universities of Henan Province 2010HASTIT025
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